I recently interviewed one of the world’s leading advertising experts. Over the course of his lifetime, he’s spent over $40 million on advertising, generated hundreds of millions for himself and his clients and is currently spending $800,000 per month, profitably.

It’s an impressive feat, especially when you consider the fact that many people want to build their online businesses and e-commerce brands with tools like Facebook and Google ads.

But due to rising ad costs, remaining profitable is harder now than ever. And yet, here he is chugging along, still making enormous profits, month after month.

I wanted to know how he does it. So I sat down with him and asked him to share his biggest advertising secrets. I wanted to know where most advertisers go wrong and what he does so different. What he shared was eye-opening and could change the way you advertise forever.

Here are the 2 biggest mistakes advertisers are making:

1. Thinking you have to have a massive budget to win

“When it comes to advertising, the biggest mistake I see people make is think it’s the people with the biggest budget who wins. It’s not. Instead, it’s the person who can build the best relationship with their customers and provide that value over and over again. If you don’t have the biggest budget to start, who gives a crap? Get customers. Treat them like gold. And find a way to sell them more stuff.”

What he was describing was having a backend to your marketing efforts — an engine that goes beyond just making one sale to one customer and helps you sell over and over again people.

For example, if you’re selling golf clubs, don’t just thinking about the clubs you sell. If that’s where you try to make all your profit, you’ll be out of business. Instead, think about how you could sell those people other things. The obvious ones are golf balls, golf shoes, a membership to a golfing club.

And even deeper, maybe their joints hurt because of repetitive stress from swinging the club?

If that’s the case, perhaps you could offer a supplement that helps with joint pain? Or refer them to a great doctor?  The list could go on and on. But the point is the first sale isn’t the end game for successful advertisers.

They make their money by acquiring a customer with little profit —  or potentially even at a loss — knowing that they can sell them something else in the future. Pulling out their wallet the first time is the beginning of the relationship. But after they do it, you can follow them around on the internet with ads and sell them more and more stuff.

Going one layer deeper with his customers is one of the key secrets to his success.

2. Trying to sell the wrong product

The other big mistake he says people make is trying to sell the wrong products. “The second biggest mistake people make is trying to sell a product that people don’t want. They think better copywriting will save them. That’s not the answer. What people should do before they even have a product to sell is set up a simple landing page with a mockup of the product on it. Take $500 and run traffic to it on Facebook. If people get to the page and hit the buy now button, you’ve got a winner.”

He added, “But don’t worry about having the product on hand. Just have an error message pop up that says, ‘We’re sorry the product is out of stock right now. But if you enter your name and email, we’ll send you a notification in 30 days where you can get it for 50% off.”

This strategy allows him to quickly find out if a product will sell or not on a budget of less than $500. The beauty is he doesn’t even have to have it on hand to find out. He can handle all the details after he knows it’s a winner. But all he needs to know if it’s worth sinking his time and money into is an image and a short landing page explaining the product.

This is so different from the way most people launch products. Most people sink months into building a website, finding the product, designing it and making sure everything is perfect before launching. And that’s why most people fail.

Yet, this is how he’s able to launch hit product after hit product. Not because he’s some kind of clairvoyant product genius but because he’s constantly testing.

You don’t need the biggest budget to make your advertising work, you just need a strategy that goes deeper than making one sale. Once you have the customer, you know their interest and have no excuse not to find other things they might love. Also, make sure to test your products before launching. With $500 and a simple landing page, you can have hit product after hit product lined up in your pipeline.